基于暂态电流行波的高原隧道钢轨断裂检测方法研究

Broken rail is an important factor threatening railway transportation safety. Especially the broken rail occured in the tunnel, which will lead to devastating consequences. Therefore, to achieve the real-time broken rail detection in the tunnel is an important measure to protect the safety of train operation..When electromagnetic wave travels in the rail and goes through rail fracture point, the reflection and refration of electromagnetic will be happened due to the transmission impedance of rail fracture point doesn't match,this phenomenon make the transient current traveling waves includes the fault character information..Taking the track circuit of centre-fed double-side current received type which have been put forward by the declarant as a detection track circuit, according to the principles of guide electromagnetic wave theory, both the analytical mode of transient current traveling waves which relate to rail states of fracture and normal and the transmission equation of transient current traveling waves will be builted.Based on the electrical parameter in the tunnel, the maximum transmission distance and signal frequency and type will be defined. The modulus maxima is fault character of transient current traveling waves. The fault character of transient waves will be drawn by applying the modulus maxima of wavelet transform, whether the rail is fracture or not, can be defined by analyzing and processing the date . .Through this research,the fault detection method based on current traveling waves can be applied in real-time rail broken detection.

断轨问题是威胁铁路运输安全的一个重要因素，特别是断轨发生在隧道内，将造成极其严重的后果。因此，实现长大隧道的全程实时钢轨断裂检测，是保障列车运行安全的重要措施。.电磁波在钢轨中传播经过钢轨断裂点时，因断裂点传输阻抗不匹配，将会发生电磁波的反射和折射，使暂态行波中包含了钢轨断裂的故障特征信息。.将申请者提出的中央发送、两端电流接受式轨道电路作为检测电路，根据导行电磁波理论，建立钢轨完整态、断裂态暂态电流行波分析模型和暂态电流行波传输方程。根据隧道内电气参数，确定检测电路最大传输距离，检测信号频率和制式。小波模极大值标志着电流行波的主要故障特征，应用小波变换的模极大值理论，提取行波信号故障特征，通过数据分析处理，确定钢轨是否断裂。.通过本项研究，能够将暂态电流行波故障检测方法应用于钢轨断裂实时检测。

本项目通过一年的研究工作，主要完成了轨道电路暂态电流行波传输模型建立和分析。在复频域求得了钢轨线路中每根钢轨电流和钢轨对地电压的通解。在一些特定条件下，求得了调整态受电端轨面电流的时域解。为实现基于电流行波的断轨检测提供了一定的理论基础。同时设计了检测轨道电路抗牵引回流电路、对信号发送系统进行了研究。